Benchmark: replace vs charAT for Capitalise helper app

Script Preparation code:

var str = 'foo bar baz';
var capstr = 'Foo bar baz';
var noop = Function.prototype;

Tests:

charAt() & slice()
if (str.charAt(0).toUpperCase() + str.slice(1) === capstr) noop();
replace()
if (str.replace(/^\w/, c => c.toUpperCase()) === capstr) noop();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
charAt() & slice()
replace()

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 3 years ago)

User agent: Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.54 Safari/537.36

Browser/OS: Chrome 94 on Windows

View result in a separate tab

Test name	Executions per second
charAt() & slice()	2516412.2 Ops/sec
replace()	1646541.5 Ops/sec

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):

LLMs can make mistakes. Check important info.

I'll break down the provided benchmark definitions, explain what's being tested, and discuss the pros and cons of different approaches.

**Benchmark Overview**

The test compares two methods for capitalizing a string's beginning character:

1. Using `charAt()` and `slice()`
2. Using `replace()`

The benchmark measures the execution speed of these two approaches on a specific input string (`"foo bar baz"`).

**Library Usage**

In this benchmark, no external libraries are explicitly mentioned. However, it does use the `Function.prototype` as part of the test setup code (`noop = Function.prototype;`). This is likely used to define an empty function that doesn't do anything.

**Special JavaScript Features/Syntax**

None of the test cases involve any special or experimental JavaScript features.

**Options Compared**

There are two options being compared:

1. **charAt() and slice()**: This method uses `str.charAt(0)` to get the first character, converts it to uppercase using `toUpperCase()`, and then concatenates the rest of the string (`str.slice(1)`) using the `+` operator.
2. **replace()**: This method uses a regular expression with the `/^\\w/` pattern to match the beginning of the string and capture the first character. The captured group is then converted to uppercase using a callback function `c => c.toUpperCase()`.

**Pros and Cons**

Here's a brief analysis of each approach:

1. **charAt() and slice()**:
	* Pros: Simple, straightforward, and easy to understand.
	* Cons: May be slower due to the overhead of calling `toUpperCase()` and concatenating strings.
2. **replace()**:
	* Pros: Can potentially be faster if the regular expression engine is optimized for this specific pattern.
	* Cons: Requires a deeper understanding of regular expressions, which can make it harder to read and maintain.

**Other Considerations**

The choice between these two approaches depends on the specific requirements and constraints of your application. If you need to perform this operation frequently or in performance-critical code, `replace()` might be a better option due to its potential for better performance. However, if readability and simplicity are more important, `charAt() and slice()` might be a better choice.

**Alternatives**

Other approaches could include:

* Using `toUpperCase()` directly on the string: `str.toUpperCase()`
* Using a custom function with a loop to iterate over the characters
* Using a different library or framework that provides an optimized implementation of this operation

Keep in mind that the performance difference between these approaches may be negligible for most use cases, and other factors like coding style, maintainability, and readability should also be considered when choosing an approach.

Related benchmarks:

replace vs charAT for Capitalise helper app (version: 0)

Compare methods for testing string's beggining character.

Comparing performance of: charAt() & slice() vs replace()

Created: 3 years ago by: Guest

Jump to the latest result

charAt() & slice()

replace()

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

Autogenerated LLM Summary (model llama3.2:3b, generated 2 months ago):